Lubricant containing an alkali metal ketone salt and acrylonitrile

ABSTRACT

Dialkyl ketones having a relatively long oil soluble alkyl group are condensed as their anions with an acrylonitrile under mild conditions to provide lubricating oil detergent additives and emulsifiers.

United States Patent [191 DeVries Mar. 27, 1973 [54] LUBRICANTCONTAINING AN ALKALI [561' 7 References Cited figgfifi UNITED STATESPATENTS 3,267,111 8/1966 Vill ..260/465.9 [75] Invent Lou's DevmsRlchmond 3,471,547 10/1969 Evans et a1. .....26o 465.3 x [73] Assignee;Chevron Rmrch Company S 3,449,400 6/1969 Evans et al. ..260/465.9

Francisco, Calif. Pnmary Examiner-Joseph P. Brust Flled! J 1970Att0meyJ. A, Buchanan, Jr., G. F. Magdeberger, C. [21] AppL No; 54,077J. Tonkm and B. G. Fehrmger Related US. Application Data ABSTRACT [62]Division of Sen No'.749314 Aug 1, 1968' Dialkyl ketones having arelatively long oil soluble alkyl group are condensed as their anionswith an acrylonitrile under mild conditions to provide lubricat- [52]333351 53331? ing oil detergent additives and emulsifiers. [51] Int. Cl.......C07c 121/00 7 Claims, No Drawings [58] Field of Search..260/465.9, 465.8

LUBRICANT CONTAINING AN ALKALI METAL KETONE SALT AND ACRYLONITRILECROSS-REFERENCE TO RELATED APPLICATIONS This application is a divisionalof application Serial No. 749,314, filed August 1, 1968.

BACKGROUND OF THE INVENTION tion of deposits.

Moreover, because of usual marketing practices, the additives should beeffective over a broad range of conditions: the additives should bestable under the hot conditions of the diesel engine, as well as providedetergency and dispersancy over the more variable temperature conditionsin the automobile engine.

The detergent must not have deleterious eflects, such as corrosion,oxidation initiation, etc., which cannot be easily and economicallyinhibited. Also, any additive which is used in lubricating oils, whichare frequently heavily compounded, must be compatible with the otheradditives included in the oils. These additives are oxidationinhibitors, viscosity index improvers, corrosion inhibitors,-extremepressure additives, etc. v

2. Description of the Prior Art Numerous patents have issued on .ashlessdetergents having nitrogen as the polar portion of the molecule. Thesepatents include U. S. Pat. No. 3,219,666, which is concerned withcarboxamides of polyamines; U. S. Pat. No. 3,275,554, which is concernedwith hydrocarbon substituted alkylene polyamines; and U. S. Pat. No.3,328,297, which is concerned with aliphatic sulfarnides of polyalkylenepolyamines. I 7

These ashless detergents show excellent detersive capability whileavoiding the presence of metals which tend to result in metal deposits.

SUMMARY OF THE INVENTION Pursuant to this invention, lubricating oildetergents and emulsifiers are prepared by combining the anion of adi-alkyl ketone, having a relatively'long chain alkyl group with anacrylonitrile under mild conditions, wherein at least 1 acrylonitrilemolecule is condensed onto the dialkyl ketone.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 2 (Kiow 5 wherein M is analkali metal of atomic number in the v (waatml wherein M, R and R are asdefined previously and is equivalent to R. Alternatively the alkalimetal salt may be a mixture of the two possible alkali metal salts.Depending on the rate at which the two alkali metal salts .react withacrylonitrile, one or two products may result. When R is disubstitutedalpha to the carbonyl or highly hindered at the alpha position, only onealkali metal salt will result. I v

In referring to acrylonitrile, it is intended to include a-alkylsubstituted acrylonitriles where the alkyl group is of from one to twocarbon atoms, i.e., methyl or ethyl. These acrylonitriles have theformula wherein Y is hydrogen or alkyl of from one to carbon atoms,preferably hydrogen.

The acrylonitrile will be used in an amount of at least 1 mole ofacrylonitrile per mole of alkali metal-salt and usually not exceeding 10moles, more usually in the range of l to 6 moles, and, preferably, inthe range of 2 to 5 moles.

The acrylonitrile may be added batchwise or incrementally to the alkalimetal salt. Preferably, the acrylonitrile is added incrementally withvigorous stirring so as to obtain relatively homogeneous diffusion ofthe acrylonitrile into the reaction mixture. Usually, the reaction iscarried out in an inert solvent. These solvents may be polar or nonpolar(hydrocarbon).

Illustrative hydrocarbon solvents include benzene,

toluene, cumene, tert.-butyl benzene, preferably, aromatic hydrocarbonsof from six to 10 carbon atoms. Other solvents include ethers, bothaliphatic and aromatic, etc. Individual solvents or mixed solvents maybe used.

The concentration of the alkali metal salt in the solvent may vary from1 weight percent to 80 weight percent, more usually of from about 10 toweight percent.

The temperature for the condensation of the acrylonitrile with thealkali metal salt will generally be at least lC. and usually of fromabout 0 to 6020C, preferably from about 10 to 45C. Elevated temperaturesare not desirable in that they may lead to undesirable poly-condensationproducts.

The time for the addition of the acrylonitrile to the alkali metal saltwill vary widely, depending on the method of addition, the amountsemployed and the equipment available. Times may vary from 5 minutes to24 hours, more usually being fromabout 30 minutes to 6 hours.

The final product will generally have at least about 0.5 weight percentnitrogen and more usually in the range of about 1 to 5 weight percentnitrogen.

The condensation of alkali metal salts of Ketones and acrylonitrile isdescribed in an article by Adams & Hauser, J. Am. Chem. Soc. 66 1220(1944).

The ketone alkali metal salt can be prepared by the reaction of anyconvenient alkali metal base with a dialkyl ketone having at least 1a-hydrogen. Conveniently, the ketone can be reacted with an alkali metalamide or alkali metal hydride with escape of ammonia or hydrogen,respectively. Or, the ketone may be reacted with a metal complex, suchas metal-aromatic hydrocarbon complexes, e.g., sodium naphthalene,sodium biphenyl, etc. Usually, from about 0.9 to 1.5 equivalents of thebase will be added per mole of ketone.

Conveniently, the reaction is carried out in an inert solvent, usuallyan aromatic hydrocarbon solvent. The solvents have been describedpreviously for use in the condensation of acrylonitrile and the anion.The temperature for the reaction will generally be in the range of about0 to 50C. The concentration of the ketone in the solvent will generallybe of from about 10 to 70 weight percent.

The reaction is easily followed by the evolution of gas. When no furthergas is evolved, acrylonitrile, heat or in solution, may then be added tothe alkali metal salt. Isolation of the alkali metal salt is notrequired.

The ketone used to form the alkali metal salt is readily prepared by theozonization of asymmetrical secondary olefins. By asymmetrical secondaryolefins is intended an olefin being disubstituted on one of the ethylenecarbon atoms. Of course, the olefin may be tertiary or quatemary, whichinherently includes the secondary olefin.

The ketones which find use will, for the most part, have the followingformula:

wherein R is an alkyl group of at least 25 carbon atoms, usually fromabout 45 carbon atoms to 200 carbon atoms. R is an oil solubilizinggroup, generally having at least 1 branch per four carbon atoms alongthe chain and more usually at least 1 branch per two carbon atoms alongthe chain. Particularly preferred groups are polypropenyl andpolyisobutenyl obtained from polypropenyl and polyisobutenyl polymers.Other R groups may include ethylene/propylene copolymers,ethyleneisobutylene co-polymers, l-butene polymers, etc. Their brancheswill generally be of from one to two carbon atoms, more usually onecarbon atom, i.e., methyl.

When ozonization is used as the method of preparation of the ketone, theketone will generally be free of other sites of olefinic unsaturation.However, one or more sites of olefinic unsaturation may be present, whenthe other olefinic site is more highly hindered than the olefin, whichit is desired to cleave.

Usually, no more than one site of unsaturation will be present, and moreusually, the alkyl groups will be saturated.

R and R are hydrogen or lower alkyl of from one to three carbon atoms,usually of only one carbon atom and, preferably, hydrogen.

The method of ozonization is described in an article by J. J. Pappas,Tetrahedron Letters 36 4273 (1966). By this method, the olefin isdissolved in an inert solvent containing a hydroxylic solvent, such asmethanol and ozone passed through the solution at temperatures below 0C.When the equivalent amount of ozone has been introduced into thesolution, the addition of ozone is stopped, and the solution spargedwith nitrogen. Then 1 equivalent of methyl sulfide per equivalent ofolefin is added and the volatile materials stripped.

EXAMPLES The following examples are offered by way of illustration andnot by way of limitation:

EXAMPLE A Into a 1-liter flask with fritted glass inlet was charged 120g. of polyisobutylene (approximately 1,000 av. mol. wt.) in 400 ml. ofdichloromethane containing 2 equivalent weights (based onpolyisobutylene) of methanol. The solution was cooled to 20C. and 1equivalent weight of ozone sparged through the solution over a period ofabout 8 hours. At the end of this time, the ozone addition was stopped,and the solution sparged with nitrogen for 1 hour. To the solution wasthen added, in small excess over stoichiometric, 1 equivalent weight ofdimethyl sulfide and the solution allowed to warm to room temperature.When sufficient time had passed, the solvent was stripped under reducedpressure (2 mm. Hg), and the residue purified by twice reprecipitatingin acetone from pentane.

The product was analyzedby an infrared spectrum which showed thecharacteristic carbonyl peak.

' EXAMPLE 1 Into a reaction vessel was charged 1.4 g. of sodium amide in50 ml. of benzene. To the mixture was added dropwise at room temperature12 g. of a product prepared as described in Example A (ketone derivedfrom polyisobutylene of approximately 1,000 average molecular weight) in50 ml. of benzene; the mixture was stirred at room temperature for 20hours. A slow evolution of gas occurred. At the end of this time, 1.91g. of acrylonitrile in ml. of ether was added, using ra'pid stirring anda dropping funnel with a capillary inlet extending under the surface ofthe liquid in order to obtain very slow and continuous addition. Theproduct was then precipitated 3 times in methanol from a pentanesolution.

An aliquot of the product was chromatographed on a small alumina column.The material which was eluted with pentane weighed 4.2 g. (40.5 weightpercent). The material eluted with 25 percent ether/75 percent pentanewas 3.65 g. (35.2 weight percent). Finally, the product eluted with 5percent methanol/95 percent pentane was 2.5 g. (24.3 weight percent).

The analysis of the original product (unchromatographed) is as follows:C, 81.2; H, 13.03; M, 3.24.

EXAMPLE II Into a reaction vessel was introduced 500 g. of ketonederived from polyisobutylene of approximately 1,000 average molecularweight (prepared as described in Example A) in toluene. The toluene wasazeotroped to remove any water. Nitrogen gas was introduced to provide anitrogen atmosphere and 63.0 g. of sodium amide added, and the reactionmixture allowed to stir for 64 hours. The product was then filteredunder nitrogen into a receiver and diluted to a total volume of 2.5liters with toluene.

To the toluene solution was then added 79.5 g. of acrylonitrile in 1,500ml. of toluene. The addition was carried out dropwise through acapillary with rapid stirring to provide a maximum dispersion of theacrylonitrile in the toluene solution. The reaction mixture remainedclear throughout the addition. When the addition was complete, thesolvent was stripped along with unreacted acrylonitrile, the pressurebeing reduced to 2 mm. Hg. The residue was then dissolved in pentane,the product reprecipitated with methanol, and the solid redissolved inpentane. The product was then isolated and analyzed: C, 80.6; H, 12.61;N, 3.82; O, 3.6.

EXAMPLE III Into a reaction vessel was introduced 410 g. of a ketonederived from polyisobutylene of approximately 1,000 average molecularweight (prepared as described in Example A) in 1,000 m1. of benzene. Tothe solution under nitrogen was added 48 g. of sodium amide and themixture allowed to stir for 24 hours, at which time the evolution of gashad'ceased. The mixture was then filtered into a receive under nitrogenand to the filtrate added dropwise 65.2 g. of acrylonitrile in 500 ml.of benzene. Some heat of reaction was noticed, the temperature rising toa maximum of 35C. At the end of the addition, the mixture was allowed tosettle, filtered, the filtrate diluted with 4 volumes of pentane, thenchilled to 0C. and filtered. The volatiles were removed by reducing thepressure to 2 mm. Hg. The residue was analyzed: C, 81.33; H, 12.33; N,2.96; O, 2.17.

EXAMPLE IV Into a reaction vessel was introduced 25 ml. of drytetrahydrofuran, 2.36 g. (1 equivalent weight) naphthalene and 0.425 g.1 equivalent weight) sodium and the mixture stirred at room temperaturefor about one hour, when all of the sodium had dissolved. To thesolution was then added 50 g. (1 equivalent weight) of a ketone derivedfrom polyisobutylene of approximately 2,700 average molecular weight(prepared as described in Example A). When the color of the solution wasdischarged, 250 ml. of dry toluene was added.

While rapidly stirring the solution, 5.9 g. (6.0 equivalent weight) ofacrylonitrile was added slowly. At the end of the addition, the mixturewas stirred for an additional hour and then methanol added. The productwas purified by repeated dissolving of the product in pentane andprecipitation with methanol.

The product was then isolated and freed of volatile materials.

Use of the Compositions in Lubricating Oils As already indicated, thecompositions of this invention find use as detergents and dispersants inlubricating oil and are found to be effective under a wide variety ofconditions; not only under the hot conditions of the diesel engine, butthe much more variable temperature conditions of the automobile engine.

The compositions of this invention may be formulated with variouslubricating fluids (hereinafter referred to as oils) which are eitherderived from natural or synthetic sources. Oils generally haveviscosities of from about 35 to 50,000 Saybolt Universal Seconds (SUS)at 100F.

Among natural hydrocarbonaceous oils are paraffin base, naphthenic base,asphaltic base and mixed base oils. Illustrative of synthetic oils are:hydrocarbon oils such as polymers of various olefins, generally of fromtwo to eight carbon atoms, and alkylated aromatic hydrocarbons; andnon-hydrocarbon oils, such as polyalkylene oxides, aromatic ethers,carboxylate esters, phosphate esters, and silicon esters. The preferredmedia are the hydrocarbonaceous media, both natural and synthetic.

The above oils may be used individually or together whenever miscible ormade so by the use of mutual solvents.

When the detergents of this invention are compounded with lubricatingoils for use in an engine, the detergents will be present in at leastabout 0.1 weight percent and usually not more than 20 weight percent,more usually in the range of about 1 to 10 weight percent. The compoundscan be prepared as concentrates due to their excellent compatibilitywith oils. As concentrates, the compounds of this invention willgenerally range from about 10 to weight percent, more usually from about20 to 50 weight percent of the total composition. 1

A preferred aspect in using the compounds of this invention inlubricating oils is to include in the oil from about 1 to 50 mM./kg. ofa dihydrocarbyl phosphorodithioate, wherein the hydrocarbyl groups arefrom about four to 36 carbon atoms. Usually, the hydrocarbyl groups willbe alkyl or alkaryl groups. The remaining valence of thephosphorodithioate will usually be satisfied by zinc, butpolyalkyleneoxy or a third hydrocarbyl group may also be used.(Hydrocarbyl is an organic radical composed solely of carbon andhydrogen which may be aliphatic, alicyclic, aromatic or a combinationthereof.)

Other additives may also be included in the oil such as pour pointdepressants, oiliness agents, antioxidants, rust inhibitors, etc.Usually, the total amount of these additives will range from about 0.1to 10 weight percent, more usually from about 0.5 to 5 weight percent.

The individual additives may vary from about 0.01 to 5 weight percent ofthe composition.

In order to demonstrate the effectiveness of the compositions of thisinvention under extremely severe engine conditions, the composition ofExample ll was compounded at 4 weight per cent in a Mid-Continent SAE 30neutral oil. Also included were 12 mM./kg. of a common oxidationinhibitor, zinc 0,0dialkylphenyl phosphorodithioate (the alkyl groupsare of from 12 to 15 carbon atoms).

The test used is a particularly severe test which is referred to as the240-BMEP (Brake Mean Effective Pressure) Caterpillar Test. Theconditions are for a supercharged Caterpillar Test, wherein the pressureof the supercharged air is 76.5 in. Hg abs., the water temperature ofthe cooling jacket is 200F., the air temperature is 100F., the oiltemperature of the bearing is 190F., the sulfur content of the fuel is0.4 weight percent, the speed of the engine is 1,000 r.p.m., and therate of fuel input is at a rate which provides 6,900 B.T.U.s per minute.The test was carried out for 120 hours, the engine being rated at both60 and 120 hours. The results are reported as follows:

TABLE I Hours Groove Deposits Land Deposits 60 47-4-O.5-0.3 190-30-10120 83-l3-0.8-0.2 465-75-15 Rated 0400, 100 being completely clean,being completely filled. Rated 0-800, 800 being completely black.

The exemplary composition was also tested for its effect on pistonvarnish in what is referred to as a Ford varnish engine test. A highlycompounded oil was used, having the following formulation: 1.47 weightper cent of Example II; 50 mM./kg. calcium as a calcium carbonateoverbased calcium mahogany sulfonate; l5 mM./kg. of zinc, 0,0-dialkylphosphorodithioate (alkyl of from four to six carbon atoms). The oilused was a mixture of Sunray DX 250 neutral oil and Sunray DX 150 brightstock in a 6.16/1 weight ratio.

The test was carried out with a 6-cylinder Ford having a 240 cubic inchdisplacement. The engine conditions are the same as the cyclicconditions of the ASTM sequence 5 B test. The engine conditions arestressed by using a dirty fuel which is comprised of 30 volume percentof a FCC heavy cut having a boiling range of from 25 3 to 424F. with 70volume percent of a commercial regular grade gasoline. The fuel has 2ml. per gallon of lead and approximately 0.1 weight per cent sulfur. Thecrankcase depression is maintained at one inch water. The engine run iscarried out for 60 hours.

The piston varnish rating was 6.3 on the basis of 0 to l0, 10 beingclean. This compared favorably to commercially available ashlessdetergents in being a comparable varnish rating.

It is evident from the above results that the compositions of thisinvention are effective lubricating oil detergents under extremelysevere temperature and oxidative conditions. Furthermore, they arecompatible with other common additives included in lubricating oil. Thecompositions are also emulsifiers and may be used to preparewater-in-oil emulsions.

I claim:

1. Compositions containing from 0.5 to 5 weight percent nitrogenprepared by combining an alkali metal salt of a ketone of the formula a.wherein said alkali metal is of atomic number 3 to b. R represents analkyl having from 25 to 200 carbon atoms; and

c. R and R each represent hydrogen or lower alkyl of from one to threecarbon atoms, with from 1 to 10 moles of an acrylonitrile per mole ofsaid salt, at a temperature in the range of from -10C. to 60C. for from5 minutes to 24 hours.

2. A composition according to claim 1, wherein said combining is carriedout in the presence of an inert solvent.

3. A composition according to claim 1, wherein R is of from 45 to 200carbon atoms, R and R are hydrogen, and said alkali metal is sodium.

4. A composition according to claim 3, wherein said acrylonitrile ispresent in from 2 to 5 moles per mole of anion.

5. A composition according to claim 1, wherein said acrylonitrile ispresent in from 2 to 5 moles and the weight percent nitrogen of thefinal product is in the range of 1 to 5.

6. A composition according to claim 5, wherein R and R are hydrogen, thesaid combining is carried out in the presence of an inert hydrocarbonsolvent and the concentration of the salt is in the range of 10 toweight percent.

7. A composition according to claim 1, wherein R is polyisobutenyl.

zg gg UNITED STATES PATENT OFFICE CERTIFICATE OF RRECTION Patent'No.2.72%J501 Dated March 27, 197% Inventor(s) LOUIS- DEVRIES It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

, 9 t d u 6 G01. 2, line 1, (RccR R should read -(RCCR R DP.

. I I R1 o Col. 2, line 17, R'C-C-CH-R2) should read Y {Y I /Y Col. 2,line Mo, "GHQ-C should read --CH2==C cN \CN Col. 2, line Mk, w "from 1to carbon, should read ---from 1 to 2 carbon.

Col. 3, line 3, from about 0 to 6020 0., should read ,--'-from about 0to 60C.'--.

Col 5, line /7, "into a receive", should read -j--into a receiver-.

Q01. 7, line 19, .speed of the engine is 1,000", should read --speed ofthe engine is 1,200--.

L Signed and sealed this 31st day of July 1973 (SEAL) Attest:

EDWARD M.PLETCHER,JR. RENE-D... 'TEGTMEYER Attestijng Officer 7 ActingCommissionef of Patents

2. A composition according to claim 1, wherein said combining is carriedout in the presence of an inert solvent.
 3. A composition according toclaim 1, wherein R3 is of from 45 to 200 carbon atoms, R4 and R5 arehydrogen, and said alkali metal is sodium.
 4. A composition according toclaim 3, wherein said acrylonitrile is present in from 2 to 5 moles permole of anion.
 5. A composition according to claim 1, wherein saidacrylonitrile is present in from 2 to 5 moles and the weight percentnItrogen of the final product is in the range of 1 to
 5. 6. Acomposition according to claim 5, wherein R4 and R5 are hydrogen, thesaid combining is carried out in the presence of an inert hydrocarbonsolvent and the concentration of the salt is in the range of 10 to 70weight percent.
 7. A composition according to claim 1, wherein R3 ispolyisobutenyl.